1. Field of the Invention
The present invention relates to optical information scanners for optically reading information attached to a goods or the like.
2. Description of the Related Art
Handheld optical information readers, such as barcode readers, aim at scanning optically readable information, such as a barcode, a two-dimensional code, or other similar codes.
For example, barcode readers are designed to:
focus light supplied from a light source, such as a light-emitting diode, thereby irradiating the focused light onto a barcode attached to a goods as an example of a target;
detect light reflected from the barcode based on the irradiated light; and
pick up an image of the barcode based on the detected light.
Specifically, barcode readers of this type normally include a handheld body case, a light source for supplying light, and an imaging optics consisting of an imaging lens and an illumination lens that focuses the irradiated light onto the whole area of a barcode.
Barcode readers also normally include a photodetector for detecting light reflected from the barcode and imaged by the imaging lens, and an electronic circuit for decoding the barcode and for communicating with external devices including a host unit, such as a register and/or a host computer. The optical or electronic components (the light source, the imaging optics, the receiving unit, and the electronic circuit) are installed in the handheld body case.
Because the handheld body case of the barcode reader has a compact size, installation of many components, such as optical or electronic components, in the case requires a great deal of time and effort. Especially, because the optical components need be disposed in the case to be optically aligned with each other precisely, it furthermore takes a lot of time and effort to install the optical components in the case.
In view of this requirement, it is desired to reduce the number of components to be installed in the barcode-reader's case as much as possible, thereby reducing time and effect required to install the components in the case.
In order to reduce the number of components to be installed in the barcode-reader's case, the applicant of this application has already proposed barcode readers designed such that the illuminating lens and the imaging lens are integrated with each other. These barcode readers are disclosed in Japanese Unexamined Patent Publication No. H11-015910.